In pursuit of what makes things heavy
Saturday, 15 March 2008
Syed Fattahul Alim
Since Democritus of ancient Greece hypothesised the everything in this universe is made up of atoms including ourselves and our sensations, the search began for unveiling the secrets of the atoms. But the search did not stop even after the actual discovery of atom and then the subatomic particles in the 19th and the 20the centuries. Large atom smashing machines in the USA and Europe are trying to find yet newer particles that might tell us about the ultimate secret of matter. For example, science is still at a loss about one of the most fundamental issues that builds our concept if matter. It is its mass. Why does matter have mass at all? Neither the classical physics of Newton, nor the modern physics of the ultimate particles armed with its quantum mechanical interpretation of things have been able to answer this profound question. So, the idea of mass of things still remains a deep mystery. But one British physicists Peter Higgs made a bold suggestion in early sixties of the last century about the existence of yet another particle, whose existence, if proved, would answer many unanswered questions. For example, why is it that we can measure only 4 per cent mass of the visible universe! Does then the rest 96 per cent, which is supposedly made of the so-called Dark Matter, account for the rest 96 per cent mass? The mysterious particle suggested by Higgs may also shed light on the secrets of 'Dark Energy' that is said to be responsible for pulling the universe further apart.
Higgs hypothesised that the universe is bathed in an invisible field through which material objects have, as it were, to wade through. The drag on things is all about mass as we know of it. But the Higgs field or the particles that go with it were not with the universe at its birth at the moment of the Big Bang. In fact, it was created a fraction of second after the Big Bang. And it is exactly since that time that the condition of heaviness was imposed on matter. And there is no reason to make light of the attribute of heaviness, for without it would not have been possible to have the galactic and the planetary systems of which the by-product we ourselves are.
Below is the story of how the idea was conceived and the search that followed to catch the elusive Higgs particle.
Until recently, few even questioned where mass comes from. Newton coined the term in 1687 in his famous tome, Principia Mathematica, and for 200 years scientists were happy to think of mass as something that simply existed. Some objects had more mass than others - a brick versus a book, say - and that was that. But scientists now know the world is not so simple. While a brick weighs as much as the atoms inside it, according to the best theory physicists have - one that has passed decades of tests with flying colours - the basic building blocks inside atoms weigh nothing at all. As matter is broken down to ever smaller constituents, from molecules to atoms to quarks, mass appears to evaporate before our eyes. Physicists have never fully understood why.
While working on the conundrum, Higgs came up with an elegant mechanism to solve the problem. It showed that at the very beginning of the universe, the smallest building blocks of nature were truly weightless, but became heavy a fraction of a second later, when the fireball of the big bang cooled. His theory was a breakthrough in itself, but something more profound dropped out of his calculations.
Higgs's theory showed that mass was produced by a new type of field that clings to particles wherever they are, dragging on them and making the heavy. Some particles find the field more sticky than others. Particles of light are oblivious to it. Others have to wade through it like an elephant in tar. So, in theory, particles can weigh nothing, but as soon as they are in the field, they get heavy.
Scientists now know that Higgs's extraordinary field, or something very similar to it, played a key role in the formation of the universe. Without it, the cosmos would not have exploded into the rich, infinite galaxies we see today. The spinning disc of cosmic dust that collapsed 4.5 billion years ago to form our solar system would never have been. No planets would have formed, nor a sun to warm them. Life would not have stood a chance.
In late summer 1964, two years before he would give his Princeton lecture, Higgs rushed out a succinct letter, packed with mathematical formulae that backed his discovery and sent it to a leading physics journal run from Cern, the European nuclear research organisation in Geneva. The paper was published almost immediately, but went largely unnoticed. Higgs planned a second paper, to emphasise his discovery, but for now that would have to wait.
In autumn 1964, he sent it to the same journal for publishing, but astonishingly the Cern editors rejected it. Evidently, it was considered "of no obvious relevance to physics". He quickly sent it to America's leading physics journal, where it appeared later that year.
Despite Cern's misgivings, Higgs's ideas now exploded into the world of theoretical physics and thousands wanted to be first to prove Higgs right. Detecting the field itself is thought to be impossible with modern technology, but Higgs also predicted a particle that is created in the field, and finding this would be the proof they sought. Officially, the particle is called the Higgs boson, but its elusive nature and fundamental role in the creation of the universe led a prominent scientist to rename it the God particle.
The name has stuck, but makes Higgs wince and raises the hackles of other theorists. "I wish he hadn't done it," he says. "I have to explain to people it was a joke. I'm an atheist, but I have an uneasy feeling that playing around with names like that could be unnecessarily offensive to people who are religious."
Strictly, the particle should bear the names of three scientists. Unknown to Higgs at the time, two Belgian physicists at the Free University in Brussels were working on the same problem. Using completely different maths, they reached the same staggering conclusion - that a never-seen field must pervade the universe and confer mass on almost everything in it. Robert Brout and François Englert didn't doubt their discovery, but checked and checked for mistakes before publishing. Their paper was published in August 1964, a few weeks before Higg's first paper, which was in press at the time.
It makes for an awkward situation, not least for Higgs, who agrees all three should share credit for the discovery. He recounts a tale when a colleague referred to the "Higgs mechanism" in a lecture in Germany more than two decades ago. In the front row, a look of displeasure flushed over one of the men in the audience. Realising his mistake, the speaker said, "Of course, I know this was also discovered by others, but I refer to it by the person with the shortest name." "My name has five letters, too," piped Brout.
A few months ago, Brout and Englert, who are close as brothers and finish each other's sentences, talked to me about the events long ago. After publishing their work, the two were having a beer on the balcony of a 17th-century cafe overlooking a Brussels park. "In the spring of 1964 we were both extremely excited," said Brout. "For the first time in my life, I felt what it might be to be a great physicist." Neither, he says, blames Higgs for their work being sidelined.
Whatever name it takes, many scientists believe that finding the particle will not only reveal the origin of mass, but will nudge open the door to a new realm of unknowns. We can see only 4% of the matter that makes up the universe. The Higgs particle may shed light on the rest - the dark matter in which galaxies form, and the dark energy that drives the expansion of the universe, for example. The particle may also shed light on string theory, an ambitious but powerful way of viewing the universe that sees every particle not as a point, but as a vibrating string of energy, where different frequencies create different particles.
Drive a few miles west from Geneva airport, with Mont Blanc behind you and the Jura mountains ahead, and you'll soon find yourself 80 metres above a giant underground particle collider, powerful enough to recreate, for a split-second, the earliest moments of the big bang. It is here at Cern, the organisation that famously rejected Higgs's idea, that the race to discover the God particle began. "Isn't that ironic?" he says.
It is a race that Higgs has followed only from the sidelines. In the decades since his discovery, he claims he struggled to keep up with the work of the new generation of bright young scientists. "The point came when people were doing things I didn't feel competent to do myself. I'm not being modest, I honestly get lost. I was lucky in spotting what I did when I did, but there comes a point where you realise what you're doing is not going to be much good."
Throughout the 90s, Cern scientists slammed particles together in their 17-mile circular accelerator and sifted through the sub-atomic wreckage for evidence of the Higgs particle. At first, they found strange signals. Some came and went with the rising of the moon, others more frequently. It was only after a lengthy investigation that they realised their multibillion machine was flexing with the tides of Lake Geneva and picking up stray currents from the TGV train, which came and went like clockwork from Geneva station down the road. Like Higgs himself, the particle remained elusive.
In summer 2000, Cern scientists working on the collider saw what looked like the first glimpse of the God particle. It was tantalising, but not enough to claim a discovery. They needed more time to prove it, but there was none. The collider was due to shut in a few months, to be replaced by a more powerful machine.
With the Cern collider out of action, the only place with a chance of finding the Higgs particle was America's Fermilab, and last December rumours hit the internet that they might have succeeded. So far, it appears to have been a false alarm, and the lab has yet to confirm the discovery.
Since Democritus of ancient Greece hypothesised the everything in this universe is made up of atoms including ourselves and our sensations, the search began for unveiling the secrets of the atoms. But the search did not stop even after the actual discovery of atom and then the subatomic particles in the 19th and the 20the centuries. Large atom smashing machines in the USA and Europe are trying to find yet newer particles that might tell us about the ultimate secret of matter. For example, science is still at a loss about one of the most fundamental issues that builds our concept if matter. It is its mass. Why does matter have mass at all? Neither the classical physics of Newton, nor the modern physics of the ultimate particles armed with its quantum mechanical interpretation of things have been able to answer this profound question. So, the idea of mass of things still remains a deep mystery. But one British physicists Peter Higgs made a bold suggestion in early sixties of the last century about the existence of yet another particle, whose existence, if proved, would answer many unanswered questions. For example, why is it that we can measure only 4 per cent mass of the visible universe! Does then the rest 96 per cent, which is supposedly made of the so-called Dark Matter, account for the rest 96 per cent mass? The mysterious particle suggested by Higgs may also shed light on the secrets of 'Dark Energy' that is said to be responsible for pulling the universe further apart.
Higgs hypothesised that the universe is bathed in an invisible field through which material objects have, as it were, to wade through. The drag on things is all about mass as we know of it. But the Higgs field or the particles that go with it were not with the universe at its birth at the moment of the Big Bang. In fact, it was created a fraction of second after the Big Bang. And it is exactly since that time that the condition of heaviness was imposed on matter. And there is no reason to make light of the attribute of heaviness, for without it would not have been possible to have the galactic and the planetary systems of which the by-product we ourselves are.
Below is the story of how the idea was conceived and the search that followed to catch the elusive Higgs particle.
Until recently, few even questioned where mass comes from. Newton coined the term in 1687 in his famous tome, Principia Mathematica, and for 200 years scientists were happy to think of mass as something that simply existed. Some objects had more mass than others - a brick versus a book, say - and that was that. But scientists now know the world is not so simple. While a brick weighs as much as the atoms inside it, according to the best theory physicists have - one that has passed decades of tests with flying colours - the basic building blocks inside atoms weigh nothing at all. As matter is broken down to ever smaller constituents, from molecules to atoms to quarks, mass appears to evaporate before our eyes. Physicists have never fully understood why.
While working on the conundrum, Higgs came up with an elegant mechanism to solve the problem. It showed that at the very beginning of the universe, the smallest building blocks of nature were truly weightless, but became heavy a fraction of a second later, when the fireball of the big bang cooled. His theory was a breakthrough in itself, but something more profound dropped out of his calculations.
Higgs's theory showed that mass was produced by a new type of field that clings to particles wherever they are, dragging on them and making the heavy. Some particles find the field more sticky than others. Particles of light are oblivious to it. Others have to wade through it like an elephant in tar. So, in theory, particles can weigh nothing, but as soon as they are in the field, they get heavy.
Scientists now know that Higgs's extraordinary field, or something very similar to it, played a key role in the formation of the universe. Without it, the cosmos would not have exploded into the rich, infinite galaxies we see today. The spinning disc of cosmic dust that collapsed 4.5 billion years ago to form our solar system would never have been. No planets would have formed, nor a sun to warm them. Life would not have stood a chance.
In late summer 1964, two years before he would give his Princeton lecture, Higgs rushed out a succinct letter, packed with mathematical formulae that backed his discovery and sent it to a leading physics journal run from Cern, the European nuclear research organisation in Geneva. The paper was published almost immediately, but went largely unnoticed. Higgs planned a second paper, to emphasise his discovery, but for now that would have to wait.
In autumn 1964, he sent it to the same journal for publishing, but astonishingly the Cern editors rejected it. Evidently, it was considered "of no obvious relevance to physics". He quickly sent it to America's leading physics journal, where it appeared later that year.
Despite Cern's misgivings, Higgs's ideas now exploded into the world of theoretical physics and thousands wanted to be first to prove Higgs right. Detecting the field itself is thought to be impossible with modern technology, but Higgs also predicted a particle that is created in the field, and finding this would be the proof they sought. Officially, the particle is called the Higgs boson, but its elusive nature and fundamental role in the creation of the universe led a prominent scientist to rename it the God particle.
The name has stuck, but makes Higgs wince and raises the hackles of other theorists. "I wish he hadn't done it," he says. "I have to explain to people it was a joke. I'm an atheist, but I have an uneasy feeling that playing around with names like that could be unnecessarily offensive to people who are religious."
Strictly, the particle should bear the names of three scientists. Unknown to Higgs at the time, two Belgian physicists at the Free University in Brussels were working on the same problem. Using completely different maths, they reached the same staggering conclusion - that a never-seen field must pervade the universe and confer mass on almost everything in it. Robert Brout and François Englert didn't doubt their discovery, but checked and checked for mistakes before publishing. Their paper was published in August 1964, a few weeks before Higg's first paper, which was in press at the time.
It makes for an awkward situation, not least for Higgs, who agrees all three should share credit for the discovery. He recounts a tale when a colleague referred to the "Higgs mechanism" in a lecture in Germany more than two decades ago. In the front row, a look of displeasure flushed over one of the men in the audience. Realising his mistake, the speaker said, "Of course, I know this was also discovered by others, but I refer to it by the person with the shortest name." "My name has five letters, too," piped Brout.
A few months ago, Brout and Englert, who are close as brothers and finish each other's sentences, talked to me about the events long ago. After publishing their work, the two were having a beer on the balcony of a 17th-century cafe overlooking a Brussels park. "In the spring of 1964 we were both extremely excited," said Brout. "For the first time in my life, I felt what it might be to be a great physicist." Neither, he says, blames Higgs for their work being sidelined.
Whatever name it takes, many scientists believe that finding the particle will not only reveal the origin of mass, but will nudge open the door to a new realm of unknowns. We can see only 4% of the matter that makes up the universe. The Higgs particle may shed light on the rest - the dark matter in which galaxies form, and the dark energy that drives the expansion of the universe, for example. The particle may also shed light on string theory, an ambitious but powerful way of viewing the universe that sees every particle not as a point, but as a vibrating string of energy, where different frequencies create different particles.
Drive a few miles west from Geneva airport, with Mont Blanc behind you and the Jura mountains ahead, and you'll soon find yourself 80 metres above a giant underground particle collider, powerful enough to recreate, for a split-second, the earliest moments of the big bang. It is here at Cern, the organisation that famously rejected Higgs's idea, that the race to discover the God particle began. "Isn't that ironic?" he says.
It is a race that Higgs has followed only from the sidelines. In the decades since his discovery, he claims he struggled to keep up with the work of the new generation of bright young scientists. "The point came when people were doing things I didn't feel competent to do myself. I'm not being modest, I honestly get lost. I was lucky in spotting what I did when I did, but there comes a point where you realise what you're doing is not going to be much good."
Throughout the 90s, Cern scientists slammed particles together in their 17-mile circular accelerator and sifted through the sub-atomic wreckage for evidence of the Higgs particle. At first, they found strange signals. Some came and went with the rising of the moon, others more frequently. It was only after a lengthy investigation that they realised their multibillion machine was flexing with the tides of Lake Geneva and picking up stray currents from the TGV train, which came and went like clockwork from Geneva station down the road. Like Higgs himself, the particle remained elusive.
In summer 2000, Cern scientists working on the collider saw what looked like the first glimpse of the God particle. It was tantalising, but not enough to claim a discovery. They needed more time to prove it, but there was none. The collider was due to shut in a few months, to be replaced by a more powerful machine.
With the Cern collider out of action, the only place with a chance of finding the Higgs particle was America's Fermilab, and last December rumours hit the internet that they might have succeeded. So far, it appears to have been a false alarm, and the lab has yet to confirm the discovery.